I don't think the CD is likely to replace print any time soon, mainly for reasons having to do with ease of handling and reading. You just can't curl up in an easy chair with a 17" monitor.

But the CD does have some possibilities in areas where it can do things that a book can't. Video footage has already been mentioned, and sound is another obvious feature.

But I think the thing that may be most important for reference purposes is the ease with which a search utility can be incorporated into a CD. That, for many books, is a major stumbling block. It's a particularly severe problem in large archives. HALI, for instance, is an essential in any good rug library, and the HALI folks have put out a cumulative index. The index goes to issue #85 (I think), and 15-20 issues are not yet indexed. The index is pretty awkward to use, and this is probably unavoidable in the print form. A search utility in the index, not a big problem on a CD, would make it much easier to use. So, here's a suggestion for Danny Shaffer and his crew: put out the HALI index on a CD with a search utility in it.